Access to the slain publicist's case pits a documentary filmmaker against Beverly Hills police as alternate theories continue to surround her 2010 murder.

Exactly three years after Hollywood publicist Ronni Chasen was gunned down as she drove home from a movie premiere, the saga is taking a new legal turn. Documentary filmmaker Ryan Katzenbach has sued the Beverly Hills Police Department in a battle over access to its case files pertaining to the Nov. 16, 2010, murder of Chasen. Police later tracked down suspect Harold Martin Smith, a 43-year-old ex-convict, who committed suicide when confronted at a flophouse in Hollywood. But Katzenbach believes there remain unanswered questions pertaining to the homicide. He is seeking to review the full investigation file for his Ed Asner-narrated project, 6:38, titled in reference to the time that elapsed between Chasen's final cell phone call and the arrival of police.

At the heart of Katzenbach's lawsuit, which he previewed for THR and filed Wednesday, is the cooperation the department previously afforded Beverly Hills Confidential, a small-press book published in 2012 that was co-authored by the department's senior forensic specialist, Clark Fogg, and journalist Barbara Schroeder. The tome delves into what its cover describes as "A Century of Stars, Scandals and Murders," with information provided directly "from the files of the Beverly Hills Police Department."

The book, whose subjects range from Charlie Chaplin to Bugsy Siegel, includes a chapter on Chasen's murder, anchored by a debunking of what Fogg, in a dialogue with Schroeder, describes as "conspiracy theorists," based on his review of evidence. Rumors persist that Smith -- who police said rode a bicycle and tried to rob Chasen in her Mercedes as she waited to turn left off of Sunset Boulevard onto Whittier Drive -- didn't act alone and might have been hired to kill Chasen and make it look like a robbery.

"He has carte blanche to everything for a book that's clearly not in his scope of duty with the department," says Katzenbach, who previously made a documentary on a 1970s domestic killing spree in Suffolk County, N.Y. "Now there should be parity across the board." (Internal department correspondence regarding the book, obtained by Katzenbach through a California Public Records Act request, shows Fogg handled some book-related work while on duty and that BHPD Chief David Snowden gave Confidential as gifts.)

In his lawsuit, Katzenbach describes the book's chapter on Chasen as presenting "a tidy version of the story congruent with the BHPD's official positions in this case," whereas the department is aware that the filmmaker's consideration "will be far more critical." Lt. Lincoln Hoshino tells THR the BHPD already has released the same amount of information to Katzenbach as it did to the co-authors -- a limited series of previously unseen crime-scene photos -- and will reveal nothing further in the case file.

The filmmaker also seeks to repeal a security hold placed on Chasen’s autopsy file that resides with the L.A. County Coroner’s Office. Such holds are typically dissolved when a case is closed.

Hoshino explains that the department was keeping the hold in place “because this one has celebrity interest to it” and it wants “to protect the family and her loved ones.” It has retained no such holds for the five other homicides that have occurred in Beverly Hills since 2007, both four closed cases as well as the high-profile unsolved murder of hairstylist Scott Ruffalo, brother of actor Mark.

When THR pointed this out and inquired about the discrepancy, Hoshino became agitated, saying that he found the line of questioning “rude” and hung up without answering.